Speaking at the Ecological Society of America (ESA) annual meeting Aug. 3-8 in Savannah, Ga., Mark Vellend will report his discovery that a significant role in seed dispersal is played by deer browsing on vegetation wherever they wish and depositing seeds, in their pellet-like feces, to germinate and produce new plants up to two miles away.
"The good news is that deer might facilitate the spread of native plants to habitats recovering from disturbance, where the seeds otherwise wouldn't be able to reach," says Vellend, a Cornell graduate student of ecology and evolutionary biology. Along with Cornell undergraduate Jonathan Myers, the graduate ecologist spent countless hours dissecting deer pellets.
The bad news, says Vellend: "Unfortunately, many of the seeds we're finding in deer feces are from noxious weeds, including four of the top 20 invasive plants of greatest concern in New York state. The multiflora rose, for example," he says of a pretty plant that creates impenetrable brambles.
Ecologists have long known about the myriad ways seeds are dispersed from plants in eastern North America: Ants carry some seeds and so does the wind, while birds and other vertebrates drop indigestible seeds in their feces. And certain plants with ballistic capabilities can shoot seeds several feet or even yards away.
Many of those methods, however, fail to account for the relatively rapid spread of some plant species when unused farmland returns to woodlands. Or the resurgence of woodlands when Ice Age glaciers scoured landscapes of all vegetation millennia ago and then receded, leaving barren soil in their wake.
The study by Vellend and his colleagues was the first comprehensive test of seed dispersal by white-tailed deer, which are known to research
Contact: Roger Segelken
Cornell University News Service